Cogging Torque Reduction in Flux-Switching Permanent-Magnet Machines by Rotor Pole Shaping

Cogging torque in flux-switching permanent-magnet (FSPM) machines is relatively high compared with that of other types of PM machines because of their unique doubly salient structure. Reducing the cogging torque in the FSPM machine is of particular importance to make it a viable alternative to conventional rotor-PM machines. A new pole shaping method has been proposed to reduce the cogging torque. The validity of the proposed method has been confirmed by analytical methods and finite-element-analysis-based simulation. The influence of the proposed pole shaping method on the back-electromotive force (EMF) and average electromagnetic torque has also been investigated.